The purpose of the proposed research is to detect pre-pulmonary edema, that is, detect elevation of the pulmonary venous pressure before it exceeds the plasma oncotic pressure and fluid escapes into the extravascular lung spaces. It has been shown experimentally and with radio-isotopes, that as pulmonary venous pressures rise, there is re-distribution of blood flow in the lungs. A method for the estimation of pulmonary venous pressures from the routine chest radiograph has been reported. We wish to apply an automated measurement system that has previously been developed for the detection of pneumoconiosis to this problem. Automated textual measurements in the spatial and spatial frequency domains will be used to characterize the pulmonary vasculature of the upper and lower lung zones, and comparisons of these regions will be made on chest radiographs of patients with normal and elevated pulmonary venous pressures. The system consists of a digital image scanner which is used for localizing lung boundaries, lung centroids, high resolution edge and texture measurements and a Fourier transform diffraction pattern sampling unit. The optical and digital subsystems are coupled through the use of a computer controlled film transport unit which permits accurate positioning of the radiograph in a laser beam for the diffraction pattern measurements. The quantitative detection of pulmonary venous pressures from the routine chest radiograph would allow the early detection of pulmonary edema on a mass-screening basis.